1. Field of the Invention
The present invention relates to a semiconductor structure, and particularly to a dynamic random access memory (DRAM) having a floating body structure and a method for fabricating the same.
2. Description of the Prior Art
The conventional DRAM device is mainly consisted of a capacitor and a transistor. As the trend continues toward miniaturization for various electronic devices, DRAM having a reduced size is also desired. However, because the capacitor occupies most space in a conventional DRAM, it is difficult to reduce the total size. Thus, a capacitorless DRAM is developed. The known capacitorless DRAM is mainly consisted of a metal-oxide-semiconductor transistor disposed on a silicon-on-insulator (SOI) type substrate, in which, a floating body on the SOI substrate serves as a charge storage region, and a source and a drain are disposed along a horizontal direction (i.e. in a direction parallel to the original surface of the substrate) in the substrate beside two side ends of the floating body, respectively. Because the floating body replaces conventional large and complicated capacitor, it saves some space.
However, with the demand of miniaturization, there is still a need for a novel memory structure having a further small size or a novel method for manufacturing the same.